Method of solubilizing steroids



2,875,214 METHOD OF SOLUBILIZIN G STEROIDS Wilbert J. Humphlett and Charles V. Wilson, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application August 9, 1956 Serial No. 603,194

14 Claims. (Cl. 260-3972) medicinal purposes, but their solubility in organic solvents v has limited their usefulness, and, therefore, it has been desired to find some way of increasing the solubility in water of these materials. Methods which have been suggested include solubilizing with materials which are not acceptable to the human system. Consequently, the nroblem of finding a solubilizing means for these very complex molecules for medicinal purposes has been complicated by the requirement that the solubilizing method provide compounds which would be acceptable to the human system.

Typical bile acids, isolated by the saponification and processing of biles of various animals, are C -substances having one carboxyl group and one, two, or three secondary alcoholic groups.

We have found that steroids can be solubilized according to our process into materials which are not only watersoluble but also can be taken into the human system .without damaging the system due to the solubilizing groups.

One object of this invention is to provide water-soluble steroids. Another object of this invention is to provide a method for solubilizing complex molecules such as those found in steroids and the like. An additional ob- ..ject is to provide a solubilizing compound which provides an amino acid on normal hydrolytic clearage which has no detrimental effect upon the human system.

We have found that these complex molecules can be solubilized by treating .the materials with a requisite amount of an isocyanato ester, and selectively hydrolyzing the ester group. The hydrolysis may be effected by use of the hydroxides or carbonates of sodium, potassium, or lithium or by other basic substances such as alkyl primary, secondary, or tertiary amines. In our preferred embodiment, the isocyanato ester is derived from glutamic .or aspartic acid,but other isocyanato esters may be used such as those derived from the simpler amino acids such as glycine, alpha-alanine, leucine, and the like.

Isocyanato esters of the structure OCN(CH ),,COR"

.or CH (CH CHNCO(CH ),,COR" may also be employed, in which n and in may be whole numbers from l-3. Isocyanato esters such as those derived from paraaminophenylacetic or para-aminophenylsuccinic acid also fall within the scope of the invention.

The following general equations illustrate the type of reaction involved:

ROH+ OCNCHRCOOR'' ROCONHCHR'COOR" ROCONHCHR'COONa RCONHCHR' COONa nited States Patent 0 30 i ix-isocyanato glutarate to yield the disodium salt of a 2,875,214 Patented Feb. 24, 1959 R represents the steroid radical or the steroid molecule less the hydroxyl group in the first equation, the steroid molecule less the carboxyl group in the second. R may be H, alkyl such as CH C H and (CH CH or aryl such as C H or CH COOR", CH CH COOR".

may be CH C H or some other lower alkyl.

The following examples are intended to be illustrative of our invention but are not intended to limit it in any Example 1.--Reaction of mixed soybean sterols with dimethyl ot-isocyanatoglutarate A solution of 5 g. (0.011 mole) of mixed soybean sterols (consisting of 24.4% stigmasterol, 69.6% B- and u-sitosterol and campesterol and 6% of long chain hydrocarbons), 2 g. (0.01 mole) of dimethyl wisocyanatohydroxide yielded a white, free-flowing powder which was readily water-soluble.

. To demonstrate the solubility of this product, 0.4 g. was dissolved in 2.5 ml. of water. The soybean sterols are insoluble in water.

.ExampIeYZr-ReactiOn of p-sit0ster0Z with dimethyl a-isocyanatoglutarate A soybean sterol, fi-sitosterol, was reacted with dimethyl water-soluble urethane as follows:

and saponified with CH3 CHCHnCH2CHCHCHa CHa CH2 C 3 a...

COzCHs O=O=N-C-H HO (omnootom then 1 J CHa OH. cnomompn-onom CH2 CH3 COzNll HGNHGOO- (0H2)2C02N81 A solution of 1.5 g. (0.0036 mole) of B-sitosterol (M. P. B L-136), 0.66 g. (0.0033 mole) of dimethyl u-isocyanato-glutarate and 25 ml. of xylene was treated in a manner identical to that in the foregoing example 0.5 g. of potassium hydroxide in 100 ml. of 95% alcohol. The product, a white, freeflowing powder, amounted to 1.8 g.

For purification the potassium salt was dissolved in water and acidified with hydrochloric acid giving a precipitate of the corresponding acid derivative. This derivative was collected, dried, and dissolved in ethyl alcohol. To this solution was added an alcohol solution containing a 5% excess of potassium hydroxide. The precipitated salt obtained melted at 286 and is readily soluble in water, e. g.1.6 g. dissolved easily in 6 ml. of Water. ,B-Sitcsterol, itself is insoluble in water.

Example 3.-Reaction of campesterol with dimethyl a-isocyanatoglutarate A solution of 2 g. (0.005 mole) of campesterol (M. P. 153156), 0.91 g. (0.0045 mole) of dimethyl OL-iSOCyanatoglutarate and 25 ml. of xylene was treated in a manner identicalto that in the foregoing example and saponified with 0.6 g. of potassium hydroxide in 100 ml. of 95% alcohol. The salt obtained amounted to 2.8 g., M. P. 281.

To demonstate the solubility of the product, a sample of 0.5 g. was readily dissolved in 1.5 ml. of water. Campesterol, itself, is insoluble in water.

The acid derivative was prepared and recrystallized twice from ethyl ether, M. P. 197-198".

N,2.4. Found: C, 71.3 H, 9.3; N, 2.8.

Example .4.-.-.-Reaction of stigmasterol wit-h dimethyl u-isocyanatoglutarate A solution of 15 g. (0.036 mole) of stigmastero1(M. P. 167-169), 6.6 g. (0.033 mole) of dimethyl u-isocyanatoglutarateand 100 ml. of xylene was treated in a 'manner identical to that in the foregoing example and saponified with "5 g. of potassium hydroxide in 200 ml.

of 95 alcohol. The product amounted to 23 g. For purification the potassium salt was dissolved in water, acidified, and the .acid .derivative which separated was extracted with ether. The combined ether phases were dried over anhydrous sodium sulfate and the ,SOlVQlltjl'fimoved. The acid derivative obtained in thismanner was dissolved in alcohol and added to a 5% excess of potassium hydroxide dissolved in alcohol. The precipitated potassium salt which was collected melts at 282.

In order to demonstrate the solubility of this product, a 1 g. sample wasreadily dissolved in 3 ml. of water. Stigmasterol, itself, is insoluble in water.

The following is the structural formula of the product:

(1H C2HB CHCH=CHCHOHCH CH3 QHa GOOK Example 5.-Reactin of stigmasterol with methyl 6-is0cyanatohexanoate A solution of 1.52 g. (0.0037 mole) of stigmasterol, 0.63 g. (0.0037 mole) of methyl o-isocyanatohexanoate (B. P. 68 at 1 mm., n 1.4448) and 100 ml. of xylene "was treated as in the foregoing example yielding the corresponding ester which, recrystallized from alcohol, amounted to'1.8 g. (89%), M. P. 99.

Analysis.Calcd. for C H O N: C, 76.1; H, 10.5;

'N,'2.4. Found: C, 76.4; H,'10.8; N, 2.1.

"This-potassium salt'can be used to prepare dilute aquepus-solutions. Stigmasterol, itself, is insoluble in water.

Example 6.-Reacti0n of testosterone with dimethyl a-isocyanatoglutarrtte Amixture of-5 g. (0.017 mole) of testosterone (M.';P.

vfor ,3xhours.

.200 -ml. of alcohol.

Example 7.Reaction of cholesterol with dimethyl a-isocyanatoglutarate Cholesterol was reacted with dimethyl a-isocyanatoglutarate to yield the disodium salt of a water-soluble urethane as follows:

then

vNaOLEI A solution of 39 g. (0.1'mole.) of cholesterol and 21g. (0.1+ mole) of dimethyl isocyanatoglutarate in 100 ml. of. chlorobenzene was heated under reflux at :120.'1'30 The chlorobenzene was removed under reduced pressure and the residual urethane-ester dissolved in about 700ml. of.alcohol. The ester crystallized therefrom-on cooling. The yield was about-49 g. (82 percent). Theester was dissolved in one liter of ethanoland treated with'7 g. (5 percent excess) of sodium hydroxide :dissolvedin 20 ml. of water. The mixture was heated ion thesteam bath foran hour, chilled,and the product --collected and'dr-ied. Yield, 47 g. The product has better solubility in water than cholesterol itself. The potassium ,salt has even greater solubility.

"Example 8.--React i0n of cholic acid with .ethyl ot-isocyanatoacetate A.-solution of..41 g. (0.1 m.) of cholic'acidand 53 g. (0.41 m.) of ethyl isocyanatoacetate in100 ml. of chlorobenzene was heated for 2 hours at the boiling point. The solvent was then-removed under reduced pressure and the resulting syrup dissolved in about 300 ml. of alcohol. To this solution was added 16 g. of sodium hydroxide (0.4 m.) dissolved in 20 ml. of water and diluted with The sodium salt separatedas a tafr'y. The mixture was warmed on the steam bath for one-half hour and then chilled. The aqueous alcohol was decanted from the pasty mass, acetone added, and the solid broken up.-.-fir st by hand, and finally by stirring vigorously with a Lightnin mixer. The acetone was removed by filtration or decantation, fresh acetone added, and, thestirringcontinued. Thegranular product (85-90 g.) was finally collected on a filter-and dried in a vacuexcellent surface-active prop CH3 H? HOOCCHaNHOOO o ONHOHEO 0 0H Analysis.Calcd. for C32H49012N3I N, .3; O, 28.8. Found: C, 57.7; H, 7.0; N, 6.0; O, 29.3. But this has not been definitely established.

The sterols are illustrated by many materials which have been found essential to the proper functioning of the human system. For example, the sex hormones are steroids and have been found necessary for the general importance to the health and well being of humans. In some situations it has been found necessary to add these materials and, therefore, the ability to make them water-soluble will further promote their use and therapeutic benefit. Insufiicient production by the human system of these hormones or of other steroids or sterols which are necessary to the human welfare, require that these be added, and, therefore, it is necessary that some means be available for supplying them to the human system which is not only acceptable to the human physiology, but which will enable these materials to perform their intended function.

Our invention provides a new means for making these steroids water-soluble and also providing a solubilizing material which itself is acceptable to the human system, inasmuch as the breakdown of these esters results in the formation of amino acids which are beneficial to the human system and which are Other compounds which may be solubilized by this procedure are the sex hormones such as estradiol, estrone, estriol, equilenin, diethylstilbesterol, testosterone, androsterone, pregnanediol,

terone, l7-hydroxydesoxycorticosterone, 17-hydroxycorticosterone, 17-hydroxyll-dehydrocorticosterone, and their derivatives.

We claim:

1. A process of solubilizing stigmasterol comprising reacting it with an isocyanato ester having the following formula 011;)..0001: in which R is an alkyl group having 1-4 carbon atoms, n is an integer from 1 to 6 and R is selected from the class consisting of hydrogen, alkyl having l-3 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

2. A composition of matter obtained by the process described in claim 1.

3. A process of solubilizing sitosterol comprising reacting it with an isocyanato ester having the following formula in which 'R is an alkyl group having 1-4 carbon atoms, n is an integer from 1 to 6 and R is selected from the class consisting of hydrogen, alkyl having 13 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

4. A composition of described in claim 3.

5. A. process of solubilizing campesterol comprising reacting it with an isocyanato ester having the following formula matter obtained by the process in which R is an alkyl group having l-4 carbon atoms, n is an integer from 1 to 6 and R' is selected from the class consisting of hydrogen, alkyl having 13 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

6. A composition of matter obtained by the process described in claim 5.

7. A process of solubilizing cholesterol. comprising reacting it with an isocyanato ester having the following formula RI OCN-ll (CH2)"C 0 OR in which R is an alkyl group having 14 carbon atoms, n is an integer from 1 to 6 and R is selected from the class consisting of hydrogen, alkyl having l-3 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

8. A composition of matter obtained by the process described in claim 7.

9. A process of solubilizing testosterone comprising reacting it with an isocyanato ester having the following formula in which R is an alkyl group having l-4 carbon atoms, n is an integer from 1 to 6 and R is selected from the class consisting of hydrogen, alkyl having 1-3 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

10. A composition of matter obtained by the process described in claim 9.

11. A process of solubilizing sterols comprising reacting a sterol with an isocyanato ester having the following formula I OGN-(RH (CH2) "C 0 OR in which R is an alkyl group having 1-4 carbon atoms, n is an integer from 1 to 6 and R is selected from the class consisting of hydrogen, alkyl having 1-3 carbon atoms and COOR, and selectively hydrolyzing the said ester linkage with alkali.

12. A composition of matter obtained by the process described in claim 11.

13. A process of solubilizing steroids selected from the class consisting of stigmasterol, sitosterol, campesterol, cholesterol, testosterone, cholic acid, estradiole, estrone, estriol, equilenin, diethylstilbesterol, androsterone, pregnanediol, cortisone, desoxycorticosterone, 11- dehydrocorticosterone, 17-hydroxydesoxycorticosterone, 17-hydroxycorticosterone, and 17-hydroxy-Il-dehydro- 7 corticpsterone by reacting the steroid with an isocyanato 14. A. composition of'matter obtained by theprocess ester having the following general formula, described in claim 13. I v

, OCN References Cited in the file of this patent H 00R 5 UNITED STATES PATENTS 2,247,822 Schwenk July 1, 1941 111 whlch R is an alkyl group having '1-4 carbon atoms, 2 333 202 Ruzicka 2 1943 n is: an. integer from 1 to 6 and R is selected from the 2:337:563

, M k 28, 1 4 class consisting of hydrogen, alkylhaving 1 to 3 carbon I at er Dgc 9 3 atoms and COOR'and selectively hydrolyzing the said 10 ester linkage with alkali. 

1. A PROCESS OF SOLUBILIZING STIGMASTEROL COMPRISING REACTING IT WITH AN ISOCYANATO ESTER HAVING THE FOLLOWING FORMULA 